A report issued by a group of obstetrician/gynecologists from Columbia University Irving Medical Center in New York City states that between March 22 and April 4, of the 215 pregnant women who delivered infants at the New York–Presbyterian Allen Hospital and Columbia University Irving Medical Center, all of whom were tested for the coronavirus COVID-19, 211 showed no symptoms, and all but one had nasopharyngeal swabs, but 29 tested positive for the virus. Thus 29 of the 33 patients who were positive for the virus at admission (87.9%) had no symptoms of Covid-19 at presentation.
As Dr. Scott Gottlieb, the commissioner of the Food and Drug Administration from 2017-19, pointed out on Twitter, “Exposure in New York to covid could be very high given emerging data on scope of prevalence.” He added, “This study suggests that in hot spots like New York City, the level of #COVID19 exposure (and rates of some immunity once serology studies are in place) could be high. Not the 50%-60% needed to confer herd immunity, but much more than 10% in hot spots like parts of New York City.”
More data on the #COVID19 attack rate in New York. Doctors screened all expectant moms at one NY hospital and found 29/210 (13.8%) were asymptomatic and positive. Exposure in New York to covid could be very high given emerging data on scope of prevalence https://t.co/olsnCC74Kl
— Scott Gottlieb, MD (@ScottGottliebMD) April 14, 2020
This study suggests that in hot spots like New York City, the level of #COVID19 exposure (and rates of some immunity once serology studies are in place) could be high. Not the 50%-66% needed to confer herd immunity, but much more than 10% in hot spots like parts of New York City.
— Scott Gottlieb, MD (@ScottGottliebMD) April 14, 2020
The authors of the report stated:
Our use of universal SARS-CoV-2 testing in all pregnant patients presenting for delivery revealed that at this point in the pandemic in New York City, most of the patients who were positive for SARS-CoV-2 at delivery were asymptomatic, and more than one of eight asymptomatic patients who were admitted to the labor and delivery unit were positive for SARS-CoV-2. Although this prevalence has limited generalizability to geographic regions with lower rates of infection, it underscores the risk of Covid-19 among asymptomatic obstetrical patients. Moreover, the true prevalence of infection may be underreported because of false negative results of tests to detect SARS-CoV-2.3.
The potential benefits of a universal testing approach include the ability to use Covid-19 status to determine hospital isolation practices and bed assignments, inform neonatal care, and guide the use of personal protective equipment. Access to such clinical data provides an important opportunity to protect mothers, babies, and health care teams during these challenging times.
On the flip side, UC San Francisco perinatologist Stephanie Gaw noted that because pregnant women are in a more immunosuppressed state, “Even with the seasonal flu, pregnant women are more likely to get it than the general population and they’re at higher risk for more severe outcomes if they do get it,” adding “We see the effect in a lot of different infections. Pregnant women will have milder symptoms, but it also means that if a pregnant woman is symptomatic, she’s probably more sick than a non-pregnant person with the same symptoms.” As pregnancy compresses the diaphragm and lung volumes, she pointed out, “So when there’s increased stress on the respiratory system, you have less backup to compensate for the increased work to breathe.”
Yet FiveThirtyEight.com reported on April 4:
According to an expert survey published by FiveThirtyEight, the number of detected cases in the United States could underestimate the true number of infected people by anywhere from a multiple of two times to 100 times. The same holds in other countries. A recent paper published by Imperial College London estimated that the true number of people who had been infected with the coronavirus in the U.K. as of March 30 was somewhere between 800,000 and 3.7 million — as compared to a reported case count through that date of just 22,141.